"Dave Plowman (News)" :
In article , The Other Mike
wrote:
On Mon, 25 Nov 2013 19:09:31 +0000 (GMT), "Dave Plowman (News)"
wrote:

Notice you've missed out ordinary cars. Over 400g per mile.

If 'ordinary' means 'gross pollutor'

A Porsche 911 or a Land Rover Discovery only put out just over 300g per
mile

Try a Dacia Sandero 99g/km

To get any meaningful comparison, you'd need to test cars and aircraft in
the same sort of way. The government figures for cars are merely for
taxation purposes.

And for comparison *between* cars, presumably.

Can anyone answer me this? ISTM that the amount of carbon coming out of
an engine is exactly the same as the amount going in. If that were
precisely true there would be an exact reciprocal relationship between
measured fuel consumption and measured emissions for a given fuel. Yet
that doesn't seem to be the case. Is that to do with the form of carbon
emitted (elemental, monoxide, dioxide) or something else?

--
Mike Barnes